New ab initio potential energy surface and quantum dynamics of the reaction H(2S) + NH(X3Σ−) → N(4S) + H2

State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
The Journal of Chemical Physics (Impact Factor: 2.95). 09/2011; 135(10):104314. DOI: 10.1063/1.3636113
Source: PubMed


A new global potential energy surface is reported for the ground state ((4)A(")) of the reaction H((2)S) + NH(X(3)Σ(-)) → N((4)S) + H(2) from a set of accurate ab initio data, which were computed using the multi-reference configuration interaction with a basis set of aug-cc-pV5Z. The many-body expansion and neural network methods have been used to construct the new potential energy surface. The topographical features of the new global potential energy surface are presented. The predicted barrier height is lower than previous theoretical estimates and the heat of reaction with zero-point energy is closer to experimental results. The quantum reactive scattering dynamics calculation was carried out over a range of collision energies (0-1.0 eV) on the new potential energy surface. The reaction probabilities, integral cross-section, and rate constants for the title reaction were calculated. The calculated rate constants are in excellent agreement with the available experimental results.

16 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: New accurate potential energy surfaces (PESs) for the lowest states (3A″ and 3A′) of the O(3P) + H2 reaction are proposed using an ab initio multireference configuration interaction method (MRCI) with Davidson correction and a large orbital basis set (aug-cc-pv5z). The many-body expansion procedure is employed to describe the analytical PES function. The topographical features of the new global PESs are presented and compared with previous surfaces. The quantum reaction scattering dynamics calculations are carried out over the collision energies range of 0.3–1.0 eV on the new PESs. The integral cross-sections and rate coefficients for the title reaction were calculated. The calculated coefficients are lower than the experimental ones at the low temperature.
    Computational and Theoretical Chemistry 04/2012; 986:25–29. DOI:10.1016/j.comptc.2012.02.002 · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this work, quasi-classical trajectory (QCT) calculations have been first carried out for the title reaction on a new global potential energy surface for the lowest quartet electronic state, 4A″. The average rotational alignment factor [P 2( j' · k )] as a function of collision energy and the two commonly used polarization dependent generalized differential cross sections PDDCS00, PDDCS20, have been calculated in the center-of-mass (CM) frame, separately. Three angular distributions, P( r), P(φ r), and P( r, φ r) are also calculated to gain insight into the alignment and the orientation of the product molecules. Calculations show that the average rotational alignment factor on the ZH PES is almost invariant with collision energies. The distributions of P( r) and P(φ r) derived from the title reaction indicate that the product polarization is strong. Validity of the QCT calculation has been examined and proven in the comparison with the quantum-wave-packet calculation results. Comparisons with available quasi-classical trajectory results are made and discussed.
    Canadian Journal of Chemistry 06/2013; 91(6). DOI:10.1139/cjc-2012-0404 · 1.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A short review of current methods for the construction of adiabatic potential energy surfaces, fundamental to rationalize the dynamics of reactive elementary gas-surface processes, is presented. Analytical fitting schemes (e.g., periodic LEPS, reactive bond-order,...) as well as numerical interpolation schemes (e.g., corrugation reducing procedure, neural networks,...) are summarized and discussed.
    Springer Series in Surface Sciences 01/2013; 50:25-50. DOI:10.1007/978-3-642-32955-5_2
Show more

Similar Publications